Missile for sporting guns



Nov. 17, 1964 R. ca. A. BLONDEAU MISSILE FOR SPORTING GUNS 2 Sheets-Sheet 1 Filed Feb. 1, 1962 Pam/v0 GILBERT Aueusrzfizawmu Arr-x Nov. 17, 1964 G. A. BLONDEAU MISSILE FOR SPORTING GUNS 2 Sheets-Sheet 2 Filed Feb. 1, 1962 hwewm? United States Patent MISSHJE FGR SPURTKNG GUNfi Roland Gilbert Auguste Blondeau, 37 Blvd. de la Repuhlique, Nevers, France Filed Feb. 1, 1962, er. No. 17%,5h9 '7 Elairns. (Cl. 1 2t2.5)

My invention has for its object a missile adapted to be used not only with sporting guns equipped with a smooth cylindrical barrel, but also with sporting guns provided with a so-called choke-bored barrel, that is wherein the inner wall of the barrel bore is provided with a cylindrical area followed by a throttled area of which the diameter gradually decreases towards the output end of the barrel.

According to my invention, the missile comprises a body including a head in the form of a circular disk, the front surface of which is fiat while its rear surface is rigidly connected to a tail-piece through an axial rod having a small section so that a deep annular recess is formed between said head and said tail-piece.

This arrangement leads to an accuracy of shooting unknown hitherto. In front of the flat front surface of the missile is formed a cone of compressed air over which slips the air in which the missile moves.

My invention also provides grooves or other similar channels or indentations in the fiat front surface of the head, which ensure stability of the compressed air cone which is formed in front of said fiat surface. Such grooves, channels or indentations improve the accuracy of shooting.

According to another feature of my invention, the body of the missile is constituted of hard metal, for instance of steel, in order to improve the power of penetration of the missile.

In this case, the head and the tail-piece of the body carry spacing shoes made of a malleable material, such as lead, and adapted to engage the inner surface of the gun barrel bore and to center said steel body inside said barrel.

The spacing shoes are adapted to be crushed so as to match the diameter of the missile with the inner diameter of the barrel. However, they must retain a thickness sufiicient for holding constantly the steel body out of contact with the inner surface of the barrel in order to avoid any risk of damaging said inner surface.

According to a preferred embodiment, the spacing shoes are constituted by two annular segments housed in peripheral grooves formed respectively in the head and in the tail-piece of the body.

The features and advantages of the invention will appear clearly from the following description given by Way 'of example, reference being made to the accompanying drawings wherein:

FIGURE 1 is a longitudinal sectional view of a missile according to my invention, shown as carried in the cylindrical area of a gun barrel of a choke-bored type;

FIGURE 2 is a similar view of a section of the same missile shown in the vicinity of the output end of the throttled area of the same barrel;

FIGURE 3 is a view of the front surface of the missile shown in FIGURE 1;

FIGURE 4 is a perspective view on a smaller scale of said missile;

FIGURE 5 is a partly sectional, partly elevational view of a cartridge for a sporting gun equipped with my improved missile;

FIGURE 6 is a side view of a missile deformed after shooting, assuming the relative shapes of the annular segments and of the grooves carrying them have not been correctly selected;

FIGURES 7 to 10 are partial cross-sections of an annular segment and of the groove carrying same, in various embodiments of my invention.

The missile 11 illustrated in the drawings is adapted for use with a sporting gun equipped with a smooth barrel 12 of the choke-bored type. In other words, the inner surface of the barrel is provided with a cylindrical area 13 (FIGURE 1) followed by a throttled area 14 (FIGURE 2) of which the diameter decreases slightly and gradually towards the output end 15 of the barrel.

, Said missile is constituted by a body 16 made of steel and including a cylindrical head 17 of a reduced axial length while its diameter is slightly less than the minimum diameter of the throttled area 14 of the gun barrel, said head carrying axially of its rear surface 18 a cylindrical rod 19 of a smaller diameter, the-diameter of said rod being for instance less than or equal to one half of the diameter of the head. The rear end of said cylindrical rod carries in its turn a tail-piece 26 including a cylindrical section 21, the diameter of which is equal to that of the head 17, said section being associated with a frusto-conical section connecting the section 21 with the rod 19. The front surface of the head 17 is provided with grooves 23, preferably annular as illustrated which thus are symmetrical about all planes that include the axis of the missile.

In the lateral cylindrical surface of each section 17 and 21, there is formed a peripheral groove 24 inside which is housed an annular spacing and centering segment 25 made of lead and of which the outer diameter is equal to or slightly larger, before the firing of the missile (see more particularly FIGURES l, 4 and 5), than the diameter of the cylindrical section 13 of the gun barrel (FIGURE 1).

For instance in the case of a sporting gun of the 20 mm. calibre for which the diameter of the barrel in the area 13 (FIGURE 1) is equal to 16 mm. while the minimum diameter of the throttled area 14- (FIGURE 2) is equal to 15.5 mm., the diameter of the cylindrical sections 17 and 21 of the steel body 16 may be equal to 15 mm. while the outer diameter of the annular segments 25 may be equal to or slightly larger than 16 mm. before the missile is shot.

Notches 27 (see FIGURE 3 in particular) are provided across the annular segment 25 at different points thereof, the depth of said notches being such that the diameter of the circle tangent to the bottom of said notches 27 may have a value ranging between the inner diameter of the cylindrical section 13 of the gun barrel and the minimum diameter of its throttled section 14. In

the above-disclosed example, the diameter of said circle may be equal to 15.8 mm.

The associated shapes of each peripheral groove 24 and of the segment 25 housed therein, are selected in a manner such that the cross-sectional area of the groove 24 is larger than the cross-sectional area of the part of the segment 25 normally engaging said groove before the firing of a shot, so as to leave inside the cross-section of said groove 24 enough room for this groove to be engaged by a portion of said part of the segment 25 lying beforethe firing, outside the groove 24. Said arrangements may be embodied in various manners. In FIG- URE 1, there is given to the groove 24 a substantially square cross-section and to the segment 25 an elliptic cross-section soas to form'between the segment and the bottom of the groove annular spaces 28. It is possible, in contradistinction, and as shown in FIGURE 7, to provide a narrower releasing groove 29 at the bottom of the groove 24, or else, it is possible, as shown in FIGURE 8, to leave a projecting annular rib 31) along thebottom of the groove, so as to form to either side of I said rib two annular depressions 31. FIGURE 9 shows how it is possible to resort to a tubular segment, and again FIGURE 10 shows a U-shaped cross-section opening inwardly for the segment 25.

The missile described hereinabove mayserve after the manner of usual bullets for sporting guns, that is, it is previously crimped inside a cartridge (FIGURE which may include the conventional cardboard sheath 40 closed at one end by a base 41 provided with a primer 39, said sheath containing in succession, starting from the base 41, a charge of gunpowder 42, a wad constituted by a stack of felt washers 43, and the actual missile 11; the

I open end 44 of the sheath 40 is crimped directly over the front surface of the missile 11, as illustrated at 45.

It will be readily understood that, at the moment of the firing of the shot, the missile 11 is projected out of the cartridge and progresses at a very high speed through the barrel 12 (FIGURES l and 2) throughout the length of the latter. During its movement through the cylindrical section 13, the annular segments 25 engage the inner surface of the barrel. As they pass through the throttled section 14 (FIGURE 2) said annular segments are crushed so as to match the reduced diameter of throttled section. They retain however a sufiicient thickness forthem to hold the steel body 16 out of contact with the inner surface of the gun barrel. Thus, no damage is to be feared for the latter.

It should be remarked that the space left in FIGURES 1 and 7 to inside the groove 24 which carries the corresponding'segment is designed so as to allow a part of the material forming the segment to recede inwardly of the groove under the action of the crushing of said segment This arrangement has for its object on the one hand to reduce the strains exerted by the segment on the throttled area of the gun barrel and on the other hand to reduce the fraction 50 (FIGURE 2) of the material forming the segment which spreads over the lateral wall of the cooperating cylindrical section 17 or 21 of the body 16. This reduction of said portion 50 missile has perforated a steel plate of a thickness of 0.25 mm. whereas at the same range and with a same charge of gun-powder, a lead missile was crushed upon impact on said steel plate without perforating the latter. Said tests were made with a sporting gun of a 20 mm. calibre with missiles weighing 24 grams and a charge of 1.5 grams of gun-powder T in the cartridge.

The particular shape given to the-steel body 16, which may be obtained sincethe steel used is both harder and lighter than lead, allows shooting with an accuracy which is far higher than that which was possible hitherto. It should be mentioned that during tests I have obtained as accuracy above three ten-thousandths of the shooting range. In other words, when shooting at a range of one hundred meters, the edges of the impacts were as an average at three centimeters from the center of the target.

front and consequently its impact is a clean one and cuts after the manner of a punch.

My invention is obviously not limitedto the embodiments disclosed byway of mere exemplifications and it has for its advantage to allow cutting out the formation of lead fashes such as 52 (FIGURE 6) which would otherwise appear along therear edges of the cylindrical sections 17 and 21, and would act detrimentally on the accuracy of the shooting by reason of the asymmetrical deformation of the missile. provided thereby.- The proper selection of the cooperating shapes given to the grooves 24v and to the segments 25, allows in contradistinction the annular grooves 23 in the front surface of the head 17 ensure an improved stability for the missile on its path. My improved missile incorporates thus a number of advantages over'conventi'onal lead missiles. By reason of its being made of steel, said missile is capable of a greater penetration since it has no tendency to be crushed or broken when impinging on a hard target after the manner of lead missiles.

covers all the modifications thereof falling within the scope of the accompanying claims. grooves 23 may assumea shape different from circularity. Malleable material other than lead may be utilized to form the segments 25. It is also possible to give the malleable spacing and centering shoes provided for the body 16 shapes different from the annular segments illustrated in the drawings and said shoes may for'instance extend longitudinally although said arrangement is less advantageous. It is also possible to provide at either end of the body 16 slots arranged in diametrical planes as shown diagrammatically in 60 in FIGURES 1 to 3, with a view to allowing the missile to expand; in order to increase said expansion, it is possible to house a charge exploding upon impact inside the body 16.

What I claim is:

1. A ballistic missile, comprising a unitary hard metal body including an enlarged frontend portionand an enlarged rear end portion of about the same diameter as the front end portion, and a midportion of a diameter not more'than about one-half the diameter of said end portions extending axially between and interconnecting said end portions, said end portions having cylindrical outer peripheries of an axial extent substantially less than their giameter, the front surface of said front end portion being 2. A ballistic missile as claimed in claim 1, the rear surface of said rear end portion being flat. I

3. A ballistic missile as claimed in claim 1, said flat front surface having at least one indentation therein, said at least one indentation being symmetrical about all planes that includethe axis of the missile. Y

4. A ballistic missile as claimed in claim 1, said flat front surface having at least one circular groove therein coaxial with the missile.

It should be mentioned-that dur- 7 ing the tests made at a range of meters, my improved a flat front surface, said flat front surfacehaving at least i one circular groove therein coaxial with'the missile.

7. A ballistic missile, comprising an integral body of steel including an enlarged front end portion and an enlarged rear end portion of about the same diameter as the In particular the front end portion, and a rnidportion of a diameter not more than about one-half the diameter of said end portions extending axially between and interconnecting said end portions, said end portions having cylindrical outer peripheries of an axial extent substantially less than their diam- 5 eter, the front surface of said front-end portion and the rear surface of said rear end portion being flat, said rear end portion terminating forwardly in a forwardly inwardly tapering surface which is a figure of revolution, and said flat front surface having at least one indentation therein 0 symmetrical about all planes that include the axis of the missile.

References Cited in the file of this patent UNITED STATES PATENTS Hotchkiss July 31, Nordenfeit J an. 2, Gully Dec. 29, Steinmetz Apr. 24, Michael Oct. 21, Donner Sept. 1, De Caro Jan. 12,

FOREIGN PATENTS Great Britain Dec. 19, 

1. A BALLISTIC MISSILE, COMPRISING A UNITARY HARD METAL BODY INCLUDING AN ENLARGED FRONT END PORTION AND AN ENLARGED REAR END PORTION OF ABOUT THE SAME DIAMETER AS THE FRONT END PORTION, AND A MIDPORTION OF A DIAMETER NOT MORE THAN ABOUT ONE-HALF THE DIAMETER OF SAID END PORTIONS EXTENDING AXIALLY BETWEEN AND INTERCONNECTING SAID END 